Well, I made a mistake. I was using TestDisk to rewrite mymissing partition. It listed my three partitions, E:/DellUtility, C: and D. However, when I chose write, I accidently had the DellUtility partition highlighted. I rebooted the server an now everytime it boots it goes to the Dell Utility tools. Any idea how to revert back?

I'm not sure I follow. How would using testdisk in a different computer help? But if it did, how would I use it in the server? When I boot the server, it automatically goes to the Utility mode after checking the NIC, RAID, PXE, etc... Even if I go to te boot menu and press enter on Primary Hard Disk, it still goes straight to the Utility.

Run TestDisk Quick Search.
If your partitions appear as green, do the following;

Check your first partition Dell Utility.
Press t für Type to change the partition type!
TestDisk opens the Partition types.
Press enter to continue.
Now at the right you see your cursor blinking.
Type de (it's the partition ID for Dell Utility).
Press enter to leave the menu.
Use your left or right arrow key to set that partition to P for primary only (please know, it's your dell utility partition and you dont boot from, that's why it's only primary).
You can see it at the left side.
Select your OS-partition like remy suggested and set it to * (Star) for active and bootable.
Press enter to continue and check Write and write your partitions (structur) to your partition table.
Close TestDisk using Quit
Restart your PC that changes will take effect.